Detection of mesial temporal lobe hypoperfusion in patients with temporal lobe epilepsy by use of arterial spin labeled perfusion MR imaging

BACKGROUND AND PURPOSE: Interictal hypometabolism has lateralizing value in cases of temporal lobe epilepsy and positive predictive value for seizure-free outcome after surgery to treat epilepsy. Alterations in regional cerebral metabolism can also be inferred from measurements of regional cerebral perfusion. The purpose of this study was to determine the feasibility of detecting cerebral blood flow (CBF) asymmetries in the mesial temporal lobes using continuous arterial spin labeling perfusion MR imaging, which is a noninvasive method for calculating regional CBF. METHODS: Twelve patients with medically refractory temporal lobe epilepsy who underwent preoperative evaluation for temporal lobectomy and 12 normal control participants were studied retrospectively. Absolute and normalized mesial temporal CBF measurements were compared between the patient and control groups. Lateralization based on a perfusion asymmetry index was compared with metabolic ((18)[F]-fluorodeoxyglucose positron emission tomography) and hippocampal volumetric asymmetry indices and with clinical lateralization. RESULTS: Mesial temporal CBF was more asymmetric in patients with temporal lobe epilepsy than in normal control participants, although asymmetric mesial temporal CBF was also found in normal participants, with the left side dominant. Ipsilateral mesial temporal CBF was significantly decreased compared with contralateral mesial temporal CBF in patients with temporal lobe epilepsy. Global CBF measurements were significantly decreased in patients compared with control participants. Asymmetry in mesial temporal blood flow in patients persisted after normalization to global CBF. Lateralization using continuous arterial spin labeling perfusion MR imaging asymmetry index significantly correlated with lateralization based on (18)[F]-fluorodeoxyglucose positron emission tomography hypometabolism, hippocampal volumes, and clinical evaluation. CONCLUSION: Continuous arterial spin labeling perfusion MR imaging can detect interictal asymmetries in mesial temporal lobe perfusion in patients with temporal lobe epilepsy. This technique is readily combined with routine structural assessment and potentially offers an inexpensive and noninvasive means of screening for asymmetries in interictal mesial temporal lobe function.     

Postsurgical prevertebral abscess of the cervical spine

OBJECTIVES: Prevertebral abscess formation is an uncommon occurrence following cervical spine fusion surgery. Abscesses may present early or in a delayed fashion and require surgical drainage and long-term antibiotic treatment. The issues of osteomyelitis and the need for plate removal remain unresolved. STUDY DESIGN: A case series of six tetraplegic patients admitted for rehabilitation to the Chaim Sheba Medical Center (Tel Hashomer, Israel) is presented. METHODS: Five patients were trauma patients; one patient underwent repeated procedures and irradiation for tumor of the cervical spine. All patients developed prevertebral abscesses after a mean period of 30 days from their fusion surgery. Computed tomography scan was used in all patients to establish the diagnosis and define the extent of the infective process. All patients underwent one or more drainage procedures. The plate was removed in two patients at 1 and 4 months. RESULTS: Infection completely resolved in four patient and was refractory in one patient with malignant tumor, and a chronic small fistula remained in one case. Staphylococcus aureus was the main infective organism, but mixed infections were the rule. Even for a protracted course of infection, no significant osteomyelitis was encountered. CONCLUSIONS: Abscess formation after instrumentation of the neck may be more common than formerly recognized. Despite the prolonged course of disease and treatment, osteomyelitis is not a major concern. There is no automatic indication for plate removal to control infection, although plating may be safely removed after 10 to 12 weeks if the neck is explored and the cervical spine is stable. A high index of suspicion is warranted, and early recognition and diagnosis, prompt surgical drainage under general anesthesia, and long-term antibiotic treatment are key for eradication of the infective process. Prophylactic antibiotics may be of value. Meticulous antisepsis and surgical technique should be maintained to reduce the incidence of these severe complications.     

Allograft dermal implant (AlloDerm) in a previously irradiated field

OBJECTIVE: To evaluate the integration of AlloDerm (LifeCell Corp., The Woodlands, TX) in a field exposed to external-beam radiation (EBR) by analyzing graft thickness, fibroblast recellularization, and neovascularization. STUDY DESIGN: Randomized control. METHODS: Thirty-six male Sprague-Dawley rats (n = 36) were randomly assigned to four groups. One hind leg of each rat was exposed to 20 Gy of EBR; the other limb served as the nonirradiated control. Two weeks after irradiation, AlloDerm was implanted into both hind legs. Grafts were harvested at 3, 4, 6, and 14 weeks after implantation and underwent histological analyses. RESULTS: There was no statistically significant difference in graft thickness, fibroblast count, or neovascularization between the grafts placed in the irradiated bed and the controls (n = 33, P = .332, P = .336, and P = .057, respectively). However, at week 3, fibroblast counts in the graft placed in the field exposed to EBR were significantly lower than those of controls (P = .019), although at week 14 the counts in the experimental limb were higher than those of the controls (P = .002). Graft thickness (P = .001) and fibroblast count (P < .004) were lower at week 14 than at earlier time periods for both the experimental and control grafts. CONCLUSIONS: In the rat model, graft thickness and neovascularization of the AlloDerm dermal implant do not appear to be adversely affected by a field that has received EBR. Fibroblast ingrowth may be hindered in the early postimplantation period but appears to normalize in the long term. Furthermore, overall graft thickness and fibroblast counts decrease over time, regardless of irradiation status.     

Neoadjuvant therapy for organ preservation in head and neck cancer

OBJECTIVES/HYPOTHESIS: We designed two sequential trials of induction chemotherapy followed by definitive radiation in patients with potentially resectable head and neck cancer to determine whether organ preservation is feasible without apparent compromise of survival Study Design Both trials were Phase II studies. METHODS: Two clinical trials were conducted sequentially at the University of Michigan. Fifty-two patients enrolled in the first study and were treated with a planned three cycles of carboplatin and 5-fluorouracil. Patients who achieved at least 50% reduction in the size of the primary tumor received definitive radiation therapy, to a dose of 6600 to 7380 cGy. Patients with minimal response or progression had immediate salvage surgery. Thirty-seven patients enrolled in the second trial, in which the chemotherapy consisted of carboplatin, 5-fluororuracil, and leukovorin. Responders were treated with accelerated radiation therapy, to a total dose of 7120 cGy delivered in 41 fractions over 5.5 weeks. RESULTS: Toxicity and response were similar in both trials; therefore, the results are reported first separately and then combined for all 89 patients. Tumor sites included: oropharynx, 55 patients; hypopharynx, 34 patients. Eighty-three percent of patients tolerated all three cycles of chemotherapy and toxicity was mild. Response to chemotherapy was: 48% complete response at the primary tumor site, and 34% partial response at the primary tumor site. Initial organ preservation at individual tumor sites was: oropharynx, 58%; hypopharynx, 59%. Median survival was 28 months, and survival at 3 and 5 years was 40% and 24%, respectively. CONCLUSIONS: These two regimens were well tolerated, and survival did not appear to be compromised by organ preservation treatment compared with historical controls. This approach warrants further investigation, particularly in those patients for whom surgery could be functionally debilitating.     

Appropriateness of routine postoperative chest radiography after tracheotomy

OBJECTIVE: To determine the appropriateness of postoperative chest radiography after adult tracheotomy. DESIGN: Retrospective case series. SETTING: Tertiary care academic medical center. PATIENTS: The records of 379 consecutive adult patients who underwent tracheotomy by the Otolaryngology-Head and Neck Surgery Service from January 1992 to December 1996 were available for review and met inclusion criteria. All patients underwent postoperative chest radiography. MAIN OUTCOME MEASURES: Frequency of postoperative tracheotomy-associated complications, most significantly pneumothorax. RESULTS: The patients had no pneumothorax on postoperative chest films. Minor complications, which were found in 7.1% of the patients, included small bleeds, wound infection, and subcutaneous emphysema. Tracheostomy-associated death occurred in 2 patients (0.5%). CONCLUSIONS: Routine postoperative chest radiography is unnecessary after adult tracheotomy. Chest radiography may be indicated by clinically suspicious signs or symptoms.     

Rev-independent expression of synthetic gag-pol genes of human immunodeficiency virus type 1 and simian immunodeficiency virus: implications for the safety of lentiviral vectors

The safety of lentiviral vectors for clinical applications is still a major concern. The gag-pol expression plasmids and the lentiviral vectors used in previous studies contain homologous regions, which constitute a risk for recombination events. Synthetic gag-pol genes of human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) were therefore constructed, in which the codon usage was optimized for expression in human cells without altering the amino acid sequences. The synthetic gag-pol genes allowed efficient expression of these genes in the absence of Rev and the 5' untranslated leader region. Both the HIV-1 and the SIV synthetic gag-pol expression plasmids could mediate transduction of an SIV vector into nondividing human cells with titers of about 10(6) transducing units/ml. Similar titers were obtained with a four-plasmid vector-packaging system based on HIV-1. Using a biological assay, homologous recombination events between the synthetic gag-pol expression plasmids and an SIV vector were undetectable and in comparison with a previously used gag-pol expression plasmid at least approximately 100-fold less frequent. By eliminating regions of homology and sequences involved in packaging, synthetic gag-pol genes should improve the safety profile of lentiviral vectors.     

Conservation laryngeal surgery for malignant tumors of the larynx and pyriform sinus

Conservation surgery for cancers of the larynx and pyriform sinus is an expansive and complicated subject. A great deal of technical expertise and clinical judgement are required for appropriate surgical and oncologic outcomes. In the appropriate setting, surgery continues to play an important role in voice preservation for patients with laryngeal and hypopharyngeal carcinoma. Perhaps most importantly, options for organ preservation surgery have expanded, and the number of patients requiring total laryngectomy as primary surgical management has decreased. The medical surgical decision making is complex and requires precise delineation of tumor extent, careful patient evaluation, and thorough interdisciplinary discussion to select an optimal course of treatment for the individual patient.     

Guess what! SALT - related B-cell lymphoma presenting as a xanthomatous infiltration of the neck

A 37-year-old man without previous medical history working as a lock keeper was seen in our unit for a progressive painless subcutaneous flesh coloured infiltration of the lower anterior area of the neck growing slowly over 5 months. Clinical cutaneous findings showed a non pruriginous yellowish papulonodular eruption mimicking xanthomas (Figs. 1 and 2). No other clinical abnormalities were found. A cutaneous biopsy specimen was performed. Histopathological examination revealed, under a normal epidermis, a dense lymphoplasmocytoid infiltrate involving the dermis with periadnexal and perivascular reinforcement (Figs. 3 and 4).